The experts said looks were obviously a major factor and further research would be conducted into that area in weeks to come.

Almost 50% of women made decisions about potential mates after half a minute during the experiment, carried out at the city's International Science Festival.

Professor Wiseman, of Hertfordshire University, said: "One in five men had made their minds up about a person within the first 30 seconds of meeting them, compared to about half of the women.

"The key thing, particularly as women are making up their minds so quickly, is that the opening line really matters."

The academic said men and women adopted a "pretty similar approach" to chat-up lines.

However, some differences between the sexes were highlighted by the study.

"It tended to be the guys that used closed questions; ones that would elicit either a yes or no answer and that would be the end of the conversation," he said.

"Our top male and female were using the same sort of chat-up lines, with topics that would make the person feel quite light-hearted.

"The most successful lines were ones which were impossible to answer with a simple yes or no, such as 'What's your favourite pizza topping?' and 'Who would you be if you were going on Stars In Their Eyes?'.

Professor Wiseman said at the other end of the spectrum, the worst chat-up lines included 'I have a PhD in computing' and 'My best friend's a helicopter pilot'.

"It's very difficult to respond to these in an interesting or creative way," he said.

The psychologist also found that those looking for a potential partner should steer clear of topics which could cause disagreement, such as favourite films.

He said: "We asked participants to talk about certain topics and when they spoke about films it was a disaster, I could just hear people arguing.

"No-one wanted to meet each other afterwards, mainly because men and women often disagree about the best types of films.

"But when you shifted the conversation to travel, everyone became a lot more energised and that ended in far more dates."